Fast gate drive for SiC-JFET using a conventional driver for MOSFETs and additional protections

Regenerative SiC frequency converter with compact Z-source DC-link and sinusoidal output voltage

“…For the loss calculation, simulation results for the inductor current during nominal operation are suitable. The Simplorer simulation (shown in Figure 8(a)) of the SiC-ZSI uses the values identified in (5)- (8). The power dissipation calculated by Matlab in each of the two inductor cores is 57 W. This is not satisfactory due to the heating of the cores.…”

“…As the avalanche gate voltage V GS,av is only about 7 V below V po , V GS,o f f must be adjusted very accurately. In [8] a "current gate driver" and a "voltage gate driver" are presented. Based on the results of that previous work, the output stage of the proposed gate drive should be a "voltage gate driver".…”

“…In [8] several strategies were compared. At last with a chip using the giant magnetoresistance effect (GMR) best results were achieved in comparison to the other examined isolation strategies in common mode immunity with a very small coupling capacity of about 4 pF and a very low propagation delay of about 10 ns.…”

“…Thus, the depending factor q is set to (7), which leads to (8) for the two DC-link capacitors: Using high switching frequencies raises additional issues to be considered for dimensioning. As for the inductors, ferromagnetic material is applied; the current ripple causes hysteresis and eddy current losses that must not be neglected.…”

“…This will be shown later. A second point must be considered for the dimensioning is the maximum ratio ν (5) between the load and the mains voltage The following calculation of the DC-link components is derived from [8]. Assuming the rated values for voltage V Load,rms = 400 V and current I Load = 12.1 A of a 7.5 kW standard induction motor, the size of both of the DC-link inductances is calculated as…”